This article is now available on the Hydrogen Audio Wiki: http://wiki.hydrogenaudio.org/index.php?ti..._Nero_AAC_Guide
Hi all,
Being both an avid Linux user and having an interest in audio compression, I was quite disappointed to find that the performance of faac to create .AAC or .MP4 files is somewhat poor (don't quote me on this, check google ). On the other hand, I've heard good things about the free Nero Digital Audio AAC encoder. The only problem is I wasn't able to find a Linux version of it.
So I decided to try out the Nero AAC encoder under Wine, using my Ubunto Linux (Dapper 6.06) operating system. To my surprise, it seems to work quite well as a command line tool. What is missing, however, is a graphical user interface.
I've always been a fan of K3b to do any of my burning/ripping/encoding of audio, so I thought I would try and interface the Nero AAC encoder with this. Basically K3b will send a raw stream of audio data to the standard input of a program you specify. We have to make sure that the output from K3b is in the correct format for the Nero AAC encoder. We do this by converting the audio stream to Microsoft .WAV format using SOX.
Recipe requirements:
. Linux (I'm using Ubuntu Dapper Drake 6.06)
. Wine (0.9.9-0ubuntu2 .deb package from Synaptic/apt-get). Wine must be set up and installed - you at least need a 'Windows' and a 'Windows\System32' directory. The encoder itself doesn't require any extra DLLs.
. Sox (12.17.9-1 .deb package from Synaptic/apt-get)
. K3b (0.12.17 compiled from source at http://k3b.plainblack.com/download )
. Nero Digital Audio Reference MPEG-4 & 3GPP Audio Encoder (1.0.0.2 downloaded from http://www.nero.com/nerodigital/eng/Nero_Digital_Audio.html )
. /dev/shm filesystem (this is often installed by default - you can get by without it, but your hard disk will end up doing more work)
Step 1 - Configure Wine
I won't go into too much detail about this here, but it's important that Wine can access all the files on your drive. I usually do this by keeping the default of Z:\ to be the 'root' (i.e. '/') filesystem. The program 'winecfg' is very useful in setting up this.
Step 2 - Install Nero Digital Audio executables
This bit is pretty easy. You just unzip the files to a directory somewhere.
You might want to test out that the executables can run by doing something like:
$ wine neroAacEnc.exe
in the 'win32' directory of the extracted files.
You should see some output like this:
err:font:ReadFontDir Can't open directory "/home/chris/.wine/dosdevices/c:/windows/Fonts"
*************************************************************
* *
* Nero Digital Audio Reference MPEG-4 & 3GPP Audio Encoder *
* Copyright (C) 2006 Nero AG *
* All Rights Reserved Worldwide *
* *
* Package build date: May 26 2006 *
* *
* See -help for a complete list of available parameters. *
* *
*************************************************************
ERROR: no input file specified
My Wine isn't set up for GUI stuff for Wine too well yet, hence the error message at the top. We don't have to worry about that though, because this is just a command line application.
Step 3 - Create 'neroaac' wrapper script
So I made a wrapper script around neroAacEnc.exe and neroAacTag.exe. The code for it is below. Copy the code into a file '/usr/local/bin/neroaac'. Make sure you chmod it to something like 755.
#!/bin/bash
TEMPFILE=/dev/shm/neroaac-$RANDOM
cd /home/chris/winec/nero/win32
sox -x -s -w -t raw -r 44100 -c 2 "$1" -w $TEMPFILE.wav
wine neroAacEnc.exe -if $TEMPFILE.wav -of $TEMPFILE.mp4
wine neroAacTag.exe $TEMPFILE.mp4 -meta:title="$3" -meta:artist="$4" -meta:comment="$5" -meta:track="$6" -meta:album="$7" -meta:year="$8"
mv $TEMPFILE.mp4 "$2"
rm $TEMPFILE.wav
IMPORTANT: Change the line that reads "cd /home/chris/winec/nero/win32" to be the directory where you have neroAacEnc.exe and neroAacTag.exe located.
Just in case you are interested, this program will take in the following parameters:
1: Source filename (or '-' for stdin). The data this script takes in will be RAW 16 bit, 44.1kHz, big endian, stereo to match the format that k3b outputs.
2: Output filename. e.g. "myfile.mp4"
3: Track Title
4: Track Artist
5: Track Comment
6: Track Number
7: Album
8: Year
It's a bit hard to test this script on its own because of the format of the input file. K3b itself doesn't even export RAW audio in this format when you have RAW selected as a format!
Step 4 - Configure K3b to use 'neroaac' as an External Plugin
I'll do this with the aid of some screenshots.
4.1. Load up K3b and start a new Audio CD project:
4.2. Drag an audio file into the project and hit the arrow button in the project with the tooltip 'Convert audio tracks to other audio formats':
4.3. In the Audio Project Conversion box that appears hit the icon that looks like a mechanical gear. You might have to change the Filetype to something like 'Flac' in order to do this:
4.4. In the next dialog box add a new program to the list and enter the following values in the 'Configure Plugin' box:
The command line is:
neroaac - %f %t %a %c %n %m %y
4.5. Close the 'Configure Plugin' box. Also close the 'Audio Project Conversion' box.
This completes the configuration of K3b. You can now use the 'Convert Audio Project' to convert any files that K3b can read into .MP4 files. Note that if you want all the meta tags (e.g. "Album") set, you will have to open the 'Burn' dialog for the Audio project and enter the CD Text information and then hit the "Save" button.
You will also be able to rip to .MP4 by selecting your CD reader/recorder in the tree and using the left-most button:
Known flaws/limitations:
. The progress bar goes to 100% quickly when converting a file and then sits there for a while. This is because K3b judges the completeness of the operation by how much of the file it has fed to the program. The program needs to take the *whole* file straight up because it needs to make a .WAV file out of it before sending it to neroAacEnc.exe. SOX will not support outputting a WAV file to a data stream.
Topic: Howto: Ripping and Encoding to Nero Digital Audio AAC in Linux (Read 20243 times)
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